Merge remote branch 'origin/feature/7986_RemoteJobTimesUI'
Protect against single-valued time series/filters when filtering logs.

Refs #7968
Remove unnecessary enable/disable of ADS observers in WorkspaceGroup

The mutex lock will already deal with queuing issues.
Refs #7968
Merge branch 'bugfix/7968_crash_filtering_single_value_time_series' into develop

Conflicts:
	Code/Mantid/Framework/API/src/WorkspaceGroup.cpp